Can I Change Colors of Demo Site?

I am finally getting around to trying to figure MODx out and wanted to know how to change the colors for the demo site to blue from green.

http://www.filmjackets.com/modx/

Which files are involved?
Where are they located?
How do I change them?

I can use Photoshop, but I am not certain which files need to be changed and how to find them.

It’s all in the CSS; take a look at the template (Elements->Manage Elements, the Templates tab) and see what .css files it’s including, and modify them.

This may help http://sottwell.com/how-templates-work.html